C++ High Performance

Smart pointers

The smart pointers from the standard library wrap a raw pointer and make the ownership of the object it points to explicit. When used correctly, there is no doubt about who is responsible for deleting a dynamic object. The three smart pointer types are std::unique_ptr, std::shared_ptr, and std::weak_ptr. As their names suggest, they represent three types of ownership of an object:

• Unique ownership expresses that I, and only I, own the object. When I'm done using it, I will delete it.
• Shared ownership expresses that I own the object along with others. When no one needs the object anymore, it will be deleted.
• Weak ownership expresses that I'll use the object if it exists, but don't keep it alive just for me.